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Theoretical insights into thermal transport and structural stability mechanisms of triaxial compressed methane hydrate
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作者 Dong-Sheng Chen Ting-Ting Miao +3 位作者 Cheng Chang Xu-Yang Guo Meng-Yan Guan and Zhong-Li Ji 《Chinese Physics B》 SCIE EI CAS CSCD 2024年第9期494-504,共11页
The heat transfer and stability of methane hydrate in reservoirs have a direct impact on the drilling and production efficiency of hydrate resources,especially in complex stress environments caused by formation subsid... The heat transfer and stability of methane hydrate in reservoirs have a direct impact on the drilling and production efficiency of hydrate resources,especially in complex stress environments caused by formation subsidence.In this study,we investigated the thermal transport and structural stability of methane hydrate under triaxial compression using molecular dynamics simulations.The results suggest that the thermal conductivity of methane hydrate increases with increasing compression strain.Two phonon transport mechanisms were identified as factors enhancing thermal conductivity.At low compressive strains,a low-frequency phonon transport channel was established due to the overlap of phonon vibration peaks between methane and water molecules.At high compressive strains,the filling of larger phonon bandgaps facilitated the opening of more phonon transport channels.Additionally,we found that a strain of0.04 is a watershed point,where methane hydrate transitions from stable to unstable.Furthermore,a strain of0.06 marks the threshold at which the diffusion capacities of methane and water molecules are at their peaks.At a higher strain of0.08,the increased volume compression reduces the available space,limiting the diffusion ability of water and methane molecules within the hydrate.The synergistic effect of the strong diffusion ability and high probability of collision between atoms increases the thermal conductivity of hydrates during the unstable period compared to the stable period.Our findings offer valuable theoretical insights into the thermal conductivity and stability of methane hydrates in reservoir stress environments. 展开更多
关键词 methane hydrate molecular dynamics thermal transport triaxial compression structural stability
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A simulation study of formation permeability as a function of methane hydrate concentration 被引量:1
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作者 赵倩 邓克俊 刘学伟 《Applied Geophysics》 SCIE CSCD 2011年第2期101-109,176,共10页
We modeled and studied the permeability of methane hydrate bearing formations as a function of methane hydrate concentration by artificially varying the T2 distribution as well as using a tube-sphere model.We varied t... We modeled and studied the permeability of methane hydrate bearing formations as a function of methane hydrate concentration by artificially varying the T2 distribution as well as using a tube-sphere model.We varied the proportion of irreducible and movable water as well as the total porosity associated with the T2 distribution and found the normalized permeability as a function of methane hydrate concentration is dependent of these variations.Using a tube-sphere model,we increased the methane hydrate concentration by randomly placing methane hydrate crystals in the pore spaces and computed the permeability using either the Schlumberger T2 relaxation time formula or a direct calculation based on Darcy's law assuming Poiseuille flow.Earlier experimental measurements reported in the literature show there is a methane hydrate concentration range where the permeability remains relatively constant.We found that when the Schlumberger T2 relaxation time formula is used the simulation results show a curve of normalized permeability versus methane hydrate concentration quite close to that predicted by the Masuda model with N = 15.When the permeability was directly calculated based on Darcy's law,the simulation results show a much higher normalized permeability and only show a trend consistent with the experimental results,i.e.,with a permeability plateau,when the methane hydrate crystals are preferentially placed in the tubes,and the higher the preferential probability,the larger the range where the permeability has a plateau. 展开更多
关键词 methane hydrate bearing formation PERMEABILITY NMR T2 distribution.
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Heat flow pattern,base of methane hydrates stability zones and BSRs in Shenhu Area,northern South China Sea 被引量:2
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作者 ZHANG Yi HE Lijuan +5 位作者 WANG Jiyang XU Xing SHA Zhibing GONG Yuehua WANG Hongbing LIANG Jinqiang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2011年第1期59-67,共9页
Using the collected 433 heat flow values, we estimated the bases of methane hydrate stability zone (BHSZ), in northern South China Sea (NSCS). Through comparing BHSZs with the depths of bottom simulating reflecto... Using the collected 433 heat flow values, we estimated the bases of methane hydrate stability zone (BHSZ), in northern South China Sea (NSCS). Through comparing BHSZs with the depths of bottom simulating reflectors (BSRs), in Shenhu Area (SA), we found that there are big differences between them. In the north of SA, where the water depth is shallow, many slumps developed and the sedimentation rate is high, it appears great negative difference (as large as -192%). However, to the southeast of SA, where the water depth is deeper, sedimentation rate is relatively low and uplift basement topography exists, it changes to positive difference (as large as +45%). The differences change so great, which haven't been observed in other places of the world. After considering the errors from the process of heat flow measurement, the BSR depth, the relationship of thermal conductivity with the sediments depth, and the fluid flow activities, we conclude that the difference should be not caused by these errors. Such big disagreement may be due to the misunderstanding of BSR. The deviant "BSRs" could represent the paleo-BSRs or just gas-bearing sediment layers, such as unconformities or the specific strata where have different permeability, which are not hydraterelated BSRs. 展开更多
关键词 methane hydrate BSR base of methane hydrate stability zone SLUMP heat flow
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Investigation of Miocene Methane Hydrate Generation Potential in the Transylvanian Basin, Romania
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作者 Unger,Z. LeClair,D. Györfi,I. 《Advances in Geological and Geotechnical Engineering Research》 2022年第2期1-8,共8页
In geology we often revise theoretical models;upon finding new evidence,such as the discovery of methane hydrates,the initial model will be challenged immediately.Hereby the authors put forward two postulates:1)There ... In geology we often revise theoretical models;upon finding new evidence,such as the discovery of methane hydrates,the initial model will be challenged immediately.Hereby the authors put forward two postulates:1)There is a third,previously unexplored source of methane in the Transylvanian Basin,based on a new theoretical approach on methane hydrate formation;2)The dissociation of methane hydrates creates a strong chlorinity anomaly.Based on a recent analogy with the Black Sea basin model,we apply our statements to the Transylvanian Basin.Using direct and indirect indicators and the published system tract analysis,we claim that there are substantial grounds to believe that this model of methane hydrate formation applies to the Miocene Transylvanian Basin.Due to the increase of the geothermal gradient as a result of the volcanic activity from the Eastern Carpathians,the clathrates dissociated into methane and freshwater.This process of dilution resulted in a chlorinity anomaly that can be spotted in the formation waters of several gas fields from the Transylvanian Basin. 展开更多
关键词 Deep hypersaline anoxic basin methane hydrates methane hydrate dissociation Chlorinity anomaly
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Methane hydrate formation and dissociation in synthetic seawater 被引量:12
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作者 Vikash Kumar Saw Iqbal Ahmad +2 位作者 Ajay Mandal G.Udayabhanu Sukumar Laik 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2012年第6期625-632,共8页
The formation and dissociation of methane gas hydrate at an interface between synthetic seawater (SSW) and methane gas have been experimentally investigated in the present work. The amount of gas consumed during hyd... The formation and dissociation of methane gas hydrate at an interface between synthetic seawater (SSW) and methane gas have been experimentally investigated in the present work. The amount of gas consumed during hydrate formation has been calculated using the real gas equation. Induction time for the formation of hydrate is found to depend on the degree of subcooling. All the experiments were conducted in quiescent system with initial cell pressure of 11.14 MPa. Salinity effects on the onset pressure and temperature of hydrate formation are also observed. The dissociation enthalpies of methane hydrate in synthetic seawater were determined by Clausius-Clapeyron equation based on the measured phase equilibrium data. The dissociation data have been analyzed by existing models and compared with the reported data. 展开更多
关键词 methane hydrate formation and dissociation total dissolved salt induction time SUBCOOLING
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Use of Electrical Resistance to Detect the Formation and Decomposition of Methane Hydrate 被引量:7
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作者 Xitang Zhou Shuanshi Fan +2 位作者 Deqing Liang Donglei Wang Ningsheng Huang 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2007年第4期399-403,共5页
The changes of electrical resistance (R) were studied experimentally in the process of CH4 hydrate formation and decomposition, using temperature and pressure as the auxiliary detecting methods simultaneously. The e... The changes of electrical resistance (R) were studied experimentally in the process of CH4 hydrate formation and decomposition, using temperature and pressure as the auxiliary detecting methods simultaneously. The experiment results show that R increases with hydrate formation and decreases with hydrate decompositon. R is more sensitive to hydrate formation and decompositon than temperature or pressure, which indicates that the detection of R will be an effective means for detecting natural gas hydrate (NGH) quantitatively. 展开更多
关键词 methane hydrate FORMATION DECOMPOSITION electrical resistance DETECTION
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The influence of temperature,pressure,salinity and capillary force on the formation of methane hydrate 被引量:3
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作者 Zhenhao Duan Ding Li +1 位作者 Yali Chen Rui Sun 《Geoscience Frontiers》 SCIE CAS 2011年第2期125-135,共11页
We present here a thermodynamic model for predicting multi-phase equilibrium of methane hydrate liquid and vapor phases under conditions of different temperature, pressure, salinity and pore sizes. The model is based ... We present here a thermodynamic model for predicting multi-phase equilibrium of methane hydrate liquid and vapor phases under conditions of different temperature, pressure, salinity and pore sizes. The model is based on the 1959 van der Waals--Platteeuw model, angle-dependent ab initio intermolecular potentials, the DMW-92 equation of state and Pitzer theory. Comparison with all available experimental data shows that this model can accurately predict the effects of temperature, pressure, salinity and capillary radius on the formation and dissociation of methane hydrate. Online calculations of the p-T conditions for the formation of methane hydrate at given salinities and pore sizes of sediments are available on: www.geochem-model.org/models.htm. 展开更多
关键词 methane hydrate ab initio potential SALINITY Porous sediment Forming conditions Phase equilibria
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Investigation on Gas Storage in Methane Hydrate 被引量:4
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作者 ZhigaoSun RongshengMa +2 位作者 ShuanshiFan KaihuaGuo RuzhuWang 《Journal of Natural Gas Chemistry》 CAS CSCD 2004年第2期107-112,共6页
The effect of additives (anionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactant alkyl polysaccharide glycoside (APG), and liquid hydrocarbon cyclopentane (CP)) on hydrate induction time and formation rat... The effect of additives (anionic surfactant sodium dodecyl sulfate (SDS), nonionic surfactant alkyl polysaccharide glycoside (APG), and liquid hydrocarbon cyclopentane (CP)) on hydrate induction time and formation rate, and storage capacity was studied in this work. Micelle surfactant solutions were found to reduce hydrate induction time, increase methane hydrate formation rate and improve methane storage capacity in hydrates. In the presence of surfactant, hydrate could form quickly in a quiescent system and the energy costs of hydrate formation were reduced. The critical micelle concentrations of SDS and APG water solutions were found to be 300×10-6 and 500×10-6 for methane hydrate formation system respectively. The effect of anionic surfactant (SDS) on methane storage in hydrates is more pronounced compared to a nonionic surfactant (APG). CP also reduced hydrate induction time and improved hydrate formation rate, but could not improve methane storage in hydrates. 展开更多
关键词 methane hydrate SURFACTANT CYCLOPENTANE gas storage
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Experimental study on characteristics of pore water conversion during methane hydrates formation in unsaturated sand 被引量:4
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作者 Yun-kai Ji Chang-ling Liu +4 位作者 Zhun Zhang Qing-guo Meng Le-le Liu Yong-chao Zhang Neng-you Wu 《China Geology》 2022年第2期276-284,共9页
Understanding the pore water conversion characteristics during hydrate formation in porous media is important to study the accumulation mechanism of marine gas hydrate.In this study,low-field NMR was used to study the... Understanding the pore water conversion characteristics during hydrate formation in porous media is important to study the accumulation mechanism of marine gas hydrate.In this study,low-field NMR was used to study the pore water conversion characteristics during methane hydrate formation in unsaturated sand samples.Results show that the signal intensity of T_(2) distribution isn’t affected by sediment type and pore pressure,but is affected by temperature.The increase in the pressure of hydrogen-containing gas can cause the increase in the signal intensity of T_(2) distribution.The heterogeneity of pore structure is aggravated due to the hydrate formation in porous media.The water conversion rate fluctuates during the hydrate formation.The sand size affects the water conversion ratio and rate by affecting the specific surface of sand in unsaturated porous media.For the fine sand sample,the large specific surface causes a large gas-water contact area resulting in a higher water conversion rate,but causes a large water-sand contact area resulting in a low water conversion ratio(C_(w)=96.2%).The clay can reduce the water conversion rate and ratio,especially montmorillonite(C_(w)=95.8%).The crystal layer of montmorillonite affects the pore water conversion characteristics by hindering the conversion of interlayer water. 展开更多
关键词 Porous media Unsaturated sand methane hydrates Low-field NMR Pore water conversion hydrate formation NGHs exploration trial engineering Oil and gas exploration engineering Shenhu area South China Sea
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Effects of Temperature Gradient and Cooling Rate on the Formation of Methane Hydrates in Coarse Sand 被引量:3
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作者 Wang Yingmei Wu Qingbai +1 位作者 Zhang Peng Jiang Guanli 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2013年第2期42-52,共11页
Temperature gradient and cooling rate have an obvious effect on formation of methane hydrate. The process for formation of methane hydrate in coarse sand is monitored to tmderstand the relationship between temperature... Temperature gradient and cooling rate have an obvious effect on formation of methane hydrate. The process for formation of methane hydrate in coarse sand is monitored to tmderstand the relationship between temperature gradient and cooling rate and nucleation, growth and distribution of methane hydrate by using the electrical resistivity method. The results show that the change of resistivity can better reflect the nucleation and growth and distribution of methane hydrate. Temperature gradient promotes the nucleation, formation, and formation rate of methane hydrate. At a temperature gradient of 0.11℃/cm, the rate of methane hydrate formation and saturation reaches a maximum. Cooling rate has little effect on the methane hydrate formation process. Judging from the outcome of final spatial distribution of methane hydrate, the cooling rate has an obvious but irregular effect in coarse sand. The effect of tempera^re gradient on distribution of methane hydrate in coarse sand is less than that of cooling rate. At a temperature gradient of 0.07℃/cm, methane hydrate is distributed uniformly in the sample. If the temperature gradient is higher or lower than this value, the hydrate is enriched in the upper layer of sample. 展开更多
关键词 methane hydrate cooling rate temperature gradient RESISTIVITY FORMATION hydrate distribution
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Experimental studies of the formation and dissociation of methane hydrate in loess 被引量:2
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作者 Guanli Jiang Qingbai Wu Jing Zhan 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2010年第3期217-223,共7页
In order to study the nature of gas hydrate in porous media,the formation and dissociation processes of methane hydrate in loess were investigated.Five cooling rates were applied to form methane hydrate.The nucleation... In order to study the nature of gas hydrate in porous media,the formation and dissociation processes of methane hydrate in loess were investigated.Five cooling rates were applied to form methane hydrate.The nucleation times of methane hydrate formation at each cooling rate were measured for comparison.The experimental results show that cooling rate is a significant factor affecting the nucleation of methane hydrate and gas conversion.Under the same initial conditions,the faster the cooling rate,the shorter the nucleation time,and the lower the methane gas conversion.Five dissociating temperatures were applied to conduct the dissociation experiment of methane hydrate formed in loess.The experimental results indicated that the temperature evidently controlled the dissociation of methane hydrate in loess and the higher the dissociating temperature,the faster the dissociating rates of methane hydrate. 展开更多
关键词 methane hydrate LOESS FORMATION DISSOCIATION NUCLEATION CONVERSION gas volume percentage
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Pore capillary pressure and saturation of methane hydrate bearing sediments 被引量:2
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作者 SUN Shicai LIU Changling +1 位作者 YE Yuguang LIU Yufeng 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2014年第10期30-36,共7页
To better understand the relationship between the pore capillary pressure and hydrate saturation in sediments, a new method was proposed. First, the phase equilibria of methane hydrate in fine-grained silica sands wer... To better understand the relationship between the pore capillary pressure and hydrate saturation in sediments, a new method was proposed. First, the phase equilibria of methane hydrate in fine-grained silica sands were measured. As to the equilibrium data, the pore capillary pressure and saturation of methane hydrate were calculated. The results showed that the phase equilibria of methane hydrates in fine-grained silica sands changed due to the depressed activity of pore water caused by the surface group and negatively charged characteristic of silica particles as well as the capillary pressure in small pores together. The capillary pressure increased with the increase of methane hydrate saturation due to the decrease of the available pore space. However, the capillary-saturation relationship could not yet be described quantitatively because of the stochastic habit of hydrate growth. 展开更多
关键词 methane hydrate equibrium silica sand SATURATION pore capillary pressure
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Water transfer characteristics during methane hydrate formation and dissociation processes inside saturated sand 被引量:3
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作者 Peng Zhang, Qingbai Wu, Yibin Pu, Guanli Jiang, Jing Zhan, Yingmei Wang State Key Laboratory, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, Gansu, China 《Journal of Natural Gas Chemistry》 CSCD 2010年第1期71-76,共6页
Gas hydrates formation and dissociation processes inside porous media are always accompanied by water transfer behavior, which is similar to the water behavior of ice freezing and thawing processes. These processes ha... Gas hydrates formation and dissociation processes inside porous media are always accompanied by water transfer behavior, which is similar to the water behavior of ice freezing and thawing processes. These processes have been studied by many researchers, but all the studies are so far on the water transfer characteristics outside porous media and the water transfer characteristics inside porous media have been little known. In this study, in order to study the water transfer characteristics inside porous media during methane hydrate formation and dissociation processes, a novel apparatus with three pF-meter sensors which can detect water content changes inside porous media was applied. It was experimentally observed that methane hydrate formation processes were accompanied by water transfer from bottom to top inside porous media, however, the water behavior during hydrate dissociation processes was abnormal, for which more studies are needed to find out the real reason in our future work. 展开更多
关键词 methane hydrate formation and dissociation processes: water transfer inside porous media saturated
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Comparison of the water change characteristics between the formation and dissociation of methane hydrate and the freezing and thawing of ice in sand 被引量:2
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作者 Peng Zhang Qingbai Wu Yingmei Wang 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2009年第2期205-210,共6页
Hydrate formation and dissociation processes are always accompanied by water migration in porous media, which is similar to the ice. In our study, a novel pF-meter sensor which could detect the changes of water conten... Hydrate formation and dissociation processes are always accompanied by water migration in porous media, which is similar to the ice. In our study, a novel pF-meter sensor which could detect the changes of water content inside sand was first applied to hydrate formation and dissociation processes. It also can study the water change characteristics in the core scale of a partially saturated silica sand sample and compare the differences of water changes between the processes of formation and dissociation of methane hydrate and freezing and thawing of ice. The experimental results showed that the water changes in the processes of formation and dissociation of methane hydrate were basically similar to that of the freezing and thawing of ice in sand. When methane hydrate or ice was formed, water changes showed the decrease in water content on the whole and the pF values rose following the formation processes. However, there were very obvious differences between the ice thawing and hydrate dissociation. 展开更多
关键词 methane hydrate ICE formation and dissociation process freezing and thawing process water change
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Water transfer characteristics in the vertical direction during methane hydrate formation and dissociation processes inside non-saturated media 被引量:2
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作者 Peng Zhang Qingbai Wu Guanli Jiang Jing Zhan Yingmei Wang 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2010年第2期139-145,共7页
In order to study water transfer characteristics inside non-saturated media during methane hydrate formation and dissociation processes,water changes on the top,middle and bottom locations of experimental media during... In order to study water transfer characteristics inside non-saturated media during methane hydrate formation and dissociation processes,water changes on the top,middle and bottom locations of experimental media during the reaction processes were continuously followed with a novel apparatus with three pF-meter sensors.Coarse sand,fine sand and loess were chosen as experimental media.It was experimentally observed that methane hydrate was easier formed inside coarse sand and fine sand than inside loess.Methane hydrate formation configuration and water transfer characteristics during methane hydrate formation processes were very different among the different non-saturated media,which were important for understanding methane hydrate formation and dissociation mechanism inside sediments in nature. 展开更多
关键词 water transfer methane hydrate formation and dissociation processes non-saturated
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Estimation of ultra-stability of methane hydrate at 1 atm by thermal conductivity measurement 被引量:2
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作者 Dongliang Li Deqing Liang +1 位作者 Shuanshi Fan Hao Peng 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2010年第3期229-233,共5页
Thermal conductivity of methane hydrate was measured in hydrate dissociation self-preservation zone by means of the transient plane source(TPS) technique developed by Gustafsson.The sample was formed from 99.9%(vol... Thermal conductivity of methane hydrate was measured in hydrate dissociation self-preservation zone by means of the transient plane source(TPS) technique developed by Gustafsson.The sample was formed from 99.9%(volume ratio) methane gas with 280 ppm sodium dodecyl sulfate(SDS) solution under 6.6 MPa and 273.15 K.The methane hydrate sample was taken out of the cell and moved into a low temperature chamber when the conversion ratio of water was more than 90%.In order to measure the thermal conductivity,the sample was compacted into two columnar parts by compact tool at 268.15 K.The measurements are carried out in the temperature ranging from 263.15 K to 271.15 K at atmospheric pressure.Additionally,the relationship between thermal conductivity and time is also investigated at 263.15 K and 268.15 K,respectively.In 24 h,thermal conductivity increases only 5.45% at 268.15 K,but thermal conductivity increases 196.29% at 263.15 K.Methane hydrates exhibit only minimal decomposition at 1 atm and the temperature ranging from 263.15 K to 271.15 K.At 1 atm and 268.15 K,the total gas that evolved after 24 h was amounted to less than 0.71% of the originally stored gas,and this ultra-stability was maintained if the test was lasted for more than two hundreds hours before terminating. 展开更多
关键词 methane hydrate SELF-PRESERVATION dissociation velocity thermal conductivity
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P-T stability conditions of methane hydrate in sediment from South China Sea 被引量:2
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作者 Shicai Sun Yuguang Ye +2 位作者 Changling Liu Fengkui Xiang Yan Ma 《Journal of Natural Gas Chemistry》 EI CAS CSCD 2011年第5期531-536,共6页
For reasonable assessment and safe exploitation of marine gas hydrate resource, it is important to determine the stability conditions of gas hydrates in marine sediment. In this paper, the seafloor water sample and se... For reasonable assessment and safe exploitation of marine gas hydrate resource, it is important to determine the stability conditions of gas hydrates in marine sediment. In this paper, the seafloor water sample and sediment sample (saturated with pore water) from Shenhu Area of South China Sea were used to synthesize methane hydrates, and the stability conditions of methane hydrates were investigated by multi-step heating dissociation method. Preliminary experimental results show that the dissociation temperature of methane hydrate both in seafloor water and marine sediment, under any given pressure, is depressed by approximately -1.4 K relative to the pure water system. This phenomenon indicates that hydrate stability in marine sediment is mainly affected by pore water ions. 展开更多
关键词 sediment from South China Sea seafloor water methane hydrate stability condition
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Structural stability of methane hydrate at high pressures 被引量:2
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作者 I.-Ming Chou Russell J.Hemley Ho-kwang Mao 《Geoscience Frontiers》 SCIE CAS 2011年第1期93-100,共8页
The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamon... The structural stability of methane hydrate under pressure at room temperature was examined by both in-situ single-crystal and powder X-ray diffraction techniques on samples with structure types I, II, and H in diamond-anvil ceils. The diffraction data for types II (slI) and H (sH) were refined to the known structures with space groups Fd3m and P63/mmc, respectively. Upon compression, sl methane hydrate transforms to the sll phase at 120 MPa, and then to the sH phase at 600 MPa. The slI methane hydrate was found to coexist locally with sI phase up to 500 MPa and with sH phase up to 600 MPa. The pure sH structure was found to be stable between 600 and 900 MPa. Methane hydrate decomposes at pressures above 3 GPa to form methane with the orientationally disordered Fm3m structure and ice VII (Pn3m). The results highlight the role of guest (CH4)-host (H2O) interactions in the stabilization of the hydrate structures under pressure. 展开更多
关键词 methane hydrate Structural stability High pressure
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Thermal Transport in Methane Hydrate by Molecular Dynamics and Phonon Inelastic Scattering 被引量:2
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作者 王照亮 苑昆鹏 唐大伟 《Chinese Physics Letters》 SCIE CAS CSCD 2015年第10期72-75,共4页
The heat conduction and thermal conductivity for methane hydrate are simulated from equilibrium molecular dynamics. The thermal conductivity and temperature dependence trend agree well with the experimental results. T... The heat conduction and thermal conductivity for methane hydrate are simulated from equilibrium molecular dynamics. The thermal conductivity and temperature dependence trend agree well with the experimental results. The nonmonotonic temperature dependence is attributed to the phonon inelastic scattering at higher temperature and to the confinement of the optic phonon modes and low frequency phonons at low temperature. The thermal conductivity scales proportionally with the van der Waals interaction strength, The conversion of a crystal-like nature into an amorphous one oecurs at higher strength. Both the temperature dependence and interaction strength dependence are explained by phonon inelastic scattering. 展开更多
关键词 Thermal Transport in methane hydrate by Molecular Dynamics and Phonon Inelastic Scattering THZ
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Experimental and modeling study of the kinetics of methane hydrate formation and dissociation 被引量:1
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作者 Vafa Feyzi Vahid Mohebbi 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2021年第1期365-374,共10页
In this work,several experiments were conducted at isobaric and isothermal condition in a CSTR reactor to study the kinetics of methane hydrate formation and dissociation.Experiments were performed at five temperature... In this work,several experiments were conducted at isobaric and isothermal condition in a CSTR reactor to study the kinetics of methane hydrate formation and dissociation.Experiments were performed at five temperatures and three pressure levels(corresponding to equilibrium pressure).Methane hydrate formation and dissociation rates were modeled using mass transfer limited kinetic models and mass transfer coefficients for both formation and dissociation were calculated.Comparison of results,shows that mass transfer coefficients for methane hydrate dissociation are one order greater than formation conditions.Mass transfer coefficients were correlated by polynomials as relations of pressure and temperature.The results and the method can be applied for prediction of methane production from naturally occurring methane hydrate deposits. 展开更多
关键词 methane hydrate KINETICS FORMATION DISSOCIATION Mass transfer
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